piano or pianoforte, musical instrument whose sound is produced by vibrating strings struck by felt hammers that are controlled from a keyboard.
The piano's earliest predecessor was the dulcimer. The first piano was made c.1709 by Bartolomeo Cristofori (1655–1731), a Florentine maker of harpsichords, who called his instrument gravicembalo col piano e forte. (One of the two existing Cristofori pianos is in the Metropolitan Mus. of Art., N.Y.C.) It differed from the harpsichord in that by varying the touch one could vary the volume and duration of tone. This expressive quality was shared by the clavichord, but the latter was far more delicate in tone.
During the 18th cent. changes in musical taste gradually favored the piano's greater volume and expressiveness, and the instrument had largely supplanted the harpsichord and clavichord by 1800. C. P. E. Bach, Mozart, Haydn, and Clementi were the first major composers to write for the piano. The main body of its enormous literature, from the 19th cent., includes the works of Beethoven, Czerny, Schubert, Chopin, Schumann, Mendelssohn, Brahms, Franck, Tchaikovsky, and Liszt. Debussy and Ravel used the special effects peculiar to the piano in highly original ways. In the 20th cent. some composers, notably Bartók, have emphasized the instrument's percussive qualities.
The piano was originally built in the shape of a harpsichord, and this style, the grand piano, has always been the standard form. It was greatly improved by the 19th-century innovation of an iron framework, best applied by the Steinways of New York City. The square piano, with strings parallel to the keys, was the most popular domestic piano until the early-19th-century perfection, in Philadelphia, of the upright piano. The English piano maker John Broadwood (1732–1812) was the first to develop the present heavier, more sonorous instrument. In 1810 the double-action striking mechanism, which permits rapid repetition of a tone, was perfected.
In the late 19th cent. a mechanical player piano was developed. A perforated paper roll was passed over a cylinder containing apertures connected to tubes that were in turn connected to the piano action. When a hole in the paper passed over an aperture, a current of air passed through a tube and caused the corresponding hammer to strike the string. The electric piano was developed in the 1930s. In the 1980s computer and compact-disc technology made possible the invention of a
an instrument designed to recreate a pianist's playing, accurately capturing the nuances of the performance. Innovative developments of the 1990s include the disklavier, a computerized grand piano that uses optical sensors to produce sound, and the two-lid piano, which opens from the top and bottom to better project sound.
See O. Bie, History of the Pianoforte (2d ed. 1966); H. Westerby, History of Pianoforte Music (1924, repr. 1970); A. Dolge, Pianos and their Makers (1911, repr. 1972); C. Ehrlich, The Piano (1976); R. Harding, The Piano-forte (1933, repr. 1978); A. Loesser, Men, Women, and Pianos (1954, repr. 1990), J. Parakilas et al., Piano Roles (2000).